Redesigning your site, migrating to a new CMS, reorganising your pages: every one of these is a chance to break URLs. Google, for its part, remembers every address it has indexed. If you change a URL without warning, it hits an error, drops the page from its results, and part of your organic traffic disappears. The worst of it is that the problem is almost always avoidable with a few simple habits.
What a broken URL really costs your SEO
Every page ranking well in Google has value: it took months to earn its place, it has collected inbound links, it generates traffic every day. When you delete or move it without a redirect, you lose all of that at once. Visitors clicking an old link hit a 404 error, Google eventually deindexes the page, and the external links that pointed at your old address no longer pass on any authority.
Practical tip: before any redesign, export the complete list of your current URLs from Google Search Console. That is your mapping document: every old URL must have a clear destination in the new version of the site.
The 301 redirect: the only type to use in SEO
- Redirect each old URL to the closest equivalent page, not systematically to the homepage
- Avoid redirect chains (URL A to B to C) which dilute your SEO value
- Never use a 302 for a permanent change
- Check that the destination really returns a 200 code, not another redirect
- Keep redirects in place for at least 12 months, the time it takes Google to fully absorb them
Spotting 404s before Google does
The 'Page indexing' report in Google Search Console lists every URL Google knows about and flags those returning a 404. It is your monitoring dashboard in the weeks following a redesign. For a fuller audit, a crawler such as Screaming Frog goes through your whole site and detects broken internal links in a few minutes.
Free tool: the free version of Screaming Frog crawls up to 500 URLs, more than enough for most small company sites. Run it just before launch, then again afterwards, and compare the two exports to spot immediately what has shifted.
Handling redirects properly is work to anticipate from the very start of a redesign, not after the fact. Our article website redesign: how to know whether it is the right moment sets out the stages to prepare upfront. And to go further on reading Search Console reports in the weeks that follow, the guide understanding your Search Console data explains what to look at first after a launch.